Communication Method and Communications Apparatus

ABSTRACT

A network device sends indication information to a terminal device, to indicate a reference position of a starting symbol of a data channel. The network device sends a physical downlink control channel to the terminal device. Then the network device sends the data channel to the terminal device, or the network device receives the data channel from the terminal device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Pat. Application No.17/037,310, filed on Sep. 29, 2020, which is a continuation ofInternational Application No. PCT/CN2019/080651, filed on Mar. 29, 2019,which claims priority to Chinese Patent Application No. 201810299099.8,filed on Apr. 4, 2018. All of the afore-mentioned patent applicationsare hereby incorporated by reference in their entireties.

TECHNICAL FIELD

This application relates to the field of communications technologies,and in particular, to a communication method and a communicationsapparatus.

BACKGROUND

In the prior art, a time domain resource table with a limited size isconfigured only by using higher layer signaling, to indicate start andlength indicator values (SLIV) of all possible time domain resources.Currently, a maximum size of the table is 16, that is, a maximum of 16combinations of starting symbols and lengths (that is, a quantity ofoccupied symbols) can be configured. In this case, if the referenceposition of the starting symbol of the data channel is constantly a slotboundary, it is equivalent to that in one slot, there are a maximum of16 possible combinations of starting symbols and lengths for datascheduling.

Because of a high reliability requirement of an ultra-reliable andlow-latency communication (URLLC) service, to ensure reliability of acontrol channel, a quantity of bits of the control channel needs to bereduced, and correspondingly, a quantity of bits of a time domainresource indicator field in the control channel also needs to bereduced. Therefore, a smaller time domain resource table needs to beconfigured. For example, four possible combinations of starting symbolsand lengths can be configured. However, for the URLLC service, because alatency requirement is relatively high, a physical downlink controlchannel (PDCCH) may be sent on any symbol in a slot. As shown in FIG. 1, potential occasions on which the URLLC service may be scheduled in aslot are occasions 1 to 7 shown in the figure. In addition, a length ofscheduled data is relatively flexible. Therefore, when a PDCCH is sent,time domain resources of a plurality of or all data channels configuredby a network device are located before a time domain resource on whichthe PDCCH is sent. Consequently, the terminal device needs to buffer allreceived data before receiving the PDCCH, in which case, a buffer of theterminal device increases and power consumption of the terminal deviceincreases.

SUMMARY

This application provides a communication method and a communicationsapparatus, to flexibly determine a reference position of a startingsymbol of a data channel.

According to a first aspect, a communication method is provided. Themethod includes: receiving first indication information from a networkdevice, where the first indication information is used to indicate areference position of a starting symbol of a data channel; receiving aphysical downlink control channel PDCCH from the network device; andreceiving the data channel from the network device based on the firstindication information and the PDCCH or sending the data channel to thenetwork device based on the first indication information and the PDCCH.

In this aspect, the reference position of the starting symbol of thedata channel is flexibly indicated by using the indication information,so that accurate receiving and sending of the data channel can beensured, and a sending occasion of the PDCCH may not be limited.

With reference to the first aspect, in a first possible implementation,the reference position includes any one of the following: a slotboundary, a starting symbol of a control resource set, an ending symbolof the control resource set, a starting symbol of a control area, anending symbol of the control area, a starting symbol of the PDCCH, andan ending symbol of the PDCCH.

With reference to the first aspect or the first possible implementationof the first aspect, in a second possible implementation, the firstindication information is associated with a terminal device, or thefirst indication information is associated with a format of downlinkcontrol information.

In this implementation, a starting symbol of the PDCCH (or an endingsymbol of the PDCCH, a starting symbol of a control resource set, anending symbol of a control resource set, a starting symbol of a controlarea, or an ending symbol of a control area) is configured for aterminal device that has an emergency service transmission requirementor a relatively high transmission reliability requirement, to serve asthe reference position of the starting symbol of the data channel, sothat the data channel can be prevented from appearing in front of acontrol channel, an amount of data buffered by the terminal device canbe reduced, and power consumption of the terminal device can be reduced.A slot boundary is configured for terminal devices that have arelatively low service latency requirement, to serve as the referenceposition, so that decrease of complexity of parsing PDCCH indicationinformation by the terminal device can be ensured. The data channel maybe received by using the slot boundary as the reference position eachtime, so that implementation complexity of the terminal device can bereduced. Similarly, resources can also be properly used by configuringdifferent reference positions for different DCI formats. For example, astarting symbol of the PDCCH (or an ending symbol of the PDCCH, astarting symbol of a control resource set, an ending symbol of a controlresource set, a starting symbol of a control area, or an ending symbolof a control area) is configured for a DCI format that is used toschedule an emergency service, to serve as a reference position of astarting symbol, so that the data channel can be prevented fromappearing in front of a control channel, an amount of data buffered bythe terminal device can be reduced, and power consumption of theterminal device can be reduced. A slot boundary is configured for DCIformats that have a relatively low latency requirement on a scheduledservice, to serve as the reference position, so that decrease ofcomplexity of parsing PDCCH indication information by the terminaldevice can be ensured. The data channel may be received by using theslot boundary as a reference position each time, so that implementationcomplexity of the terminal device can be reduced.

With reference to the first aspect, the first possible implementation ofthe first aspect, or the second possible implementation of the firstaspect, in a third possible implementation, the method further includes:receiving higher layer signaling from the network device, where thehigher layer signaling includes at least one set of an index of astarting symbol of a data channel and a quantity of symbols occupied bythe data channel.

With reference to the third possible implementation of the first aspect,in a fourth possible implementation, the method further includes: whenthe higher layer signaling includes one set of an index S1 of a startingsymbol and a quantity L1 of occupied symbols, determining that aconfiguration value S of an index of the starting symbol of the datachannel is equal to S1 and a configuration value L of the quantity ofsymbols occupied by the data channel is equal to L1; or when the higherlayer signaling includes at least two sets of indexes of startingsymbols and quantities of occupied symbols, an index of a startingsymbol indicated by the PDCCH is S2, and a quantity of occupied symbolsis L2, determining that a configuration value S of an index of thestarting symbol of the data channel is equal to S2 and a configurationvalue L of the quantity of symbols occupied by the data channel is equalto L2, where the index S2 of the starting symbol and the quantity L2 ofoccupied symbols are one set of the at least two sets of the indexes ofthe starting symbols and the quantities of occupied symbols.

In this implementation, when only one set of the index S1 of thestarting symbol and the quantity L1 of occupied symbols are configuredin the higher layer signaling, it is determined that a configurationvalue of the index of the starting symbol of the data channel is S1configured in the higher layer signaling, a configuration value of thequantity of symbols occupied by the data channel is L1 configured in thehigher layer signaling, and the PDCCH may not include indicationinformation, thereby reducing bit overheads of the PDCCH. When aplurality of sets of indexes of starting symbols and quantities ofoccupied symbols are configured in the higher layer signaling, aconfiguration value of the starting symbol of the data channel and aconfiguration value of the quantity of occupied symbols are indicated bythe PDCCH.

With reference to the fourth possible implementation of the firstaspect, in a fifth possible implementation, the reference position is aslot boundary, and the receiving the data channel from the networkdevice based on the first indication information and the PDCCH orsending the data channel to the network device based on the firstindication information and the PDCCH includes: when an index T of thestarting symbol of the PDCCH is greater than or equal to theconfiguration value S of the index of the starting symbol of the datachannel, determining that a real value S(real) of the index of thestarting symbol of the data channel is equal to the index T of thestarting symbol of the PDCCH, and a real value L(real) of the quantityof symbols occupied by the data channel is equal to: the configurationvalue L of the quantity of symbols occupied by the data channel, or asmaller value between the configuration value L of the quantity ofsymbols occupied by the data channel and a difference between a quantityof symbols included in one slot and S(real); and receiving the datachannel from the network device based on the real value of the index ofthe starting symbol of the data channel and the real value of thequantity of symbols occupied by the data channel or sending the datachannel to the network device based on the real value of the index ofthe starting symbol of the data channel and the real value of thequantity of symbols occupied by the data channel.

In this implementation, an indicated slot boundary is used as thereference position. By comparing a configuration value of the index ofthe starting symbol of the PDCCH with the configuration value of theindex of the starting symbol of the data channel, the real value of theindex of the starting symbol of the data channel and the real value ofthe quantity of symbols occupied by the data channel can be accuratelydetermined. Therefore, data is received accurately. When the PDCCH islocated after the configuration value of the index of the startingsymbol of the data channel, the real value of the index of the startingsymbol of the data channel is determined according to the rule, so thatit can be ensured that the data channel is always after the PDCCH,thereby reducing an amount of data buffered by the terminal device, andreducing power consumption of the terminal device. According to thisrule, the real value of the quantity of occupied symbols can ensure thatdata scheduling is limited within one slot and does not cross a slotboundary, thereby reducing communication complexity.

With reference to the fourth possible implementation of the firstaspect, in a sixth possible implementation, the reference position is aslot boundary, and the receiving the data channel from the networkdevice based on the first indication information and the PDCCH orsending the data channel to the network device based on the firstindication information and the PDCCH includes: when an index T of thestarting symbol of the PDCCH is less than or equal to the configurationvalue S of the index of the starting symbol of the data channel,determining that a real value S(real) of the index of the startingsymbol of the data channel is equal to the configuration value S of theindex of the starting symbol of the data channel, and a real valueL(real) of the quantity of symbols occupied by the data channel is equalto the configuration value L of the quantity of symbols occupied by thedata channel; and receiving the data channel from the network devicebased on the real value of the index of the starting symbol of the datachannel and the real value of the quantity of symbols occupied by thedata channel or sending the data channel to the network device based onthe real value of the index of the starting symbol of the data channeland the real value of the quantity of symbols occupied by the datachannel.

In this implementation, an indicated slot boundary is used as thereference position. By comparing a configuration value of the index ofthe starting symbol of the PDCCH with the configuration value of theindex of the starting symbol of the data channel, the real value of theindex of the starting symbol of the data channel and the real value ofthe quantity of symbols occupied by the data channel can be accuratelydetermined. Therefore, data is received accurately. When the PDCCH islocated before the configuration value of the index of the startingsymbol of the data channel, it is determined, according to this rule,that the real value of the index of the starting symbol of the datachannel and the real value of the quantity of symbols occupied by thedata channel are respectively equal to the configuration values, so thatparsing complexity of the terminal device can be reduced.

With reference to the fourth possible implementation of the firstaspect, in a seventh possible implementation, the reference position isa slot boundary, and the receiving the data channel from the networkdevice based on the first indication information and the PDCCH orsending the data channel to the network device based on the firstindication information and the PDCCH includes: when an index T of thestarting symbol of the PDCCH is less than or equal to the configurationvalue S of the index of the starting symbol of the data channel,determining that a real value S(real) of the index of the startingsymbol of the data channel is equal to the index T of the startingsymbol of the PDCCH, and a real value L(real) of the quantity of symbolsoccupied by the data channel is equal to the configuration value L ofthe quantity of symbols occupied by the data channel; and receiving thedata channel from the network device based on the real value of theindex of the starting symbol of the data channel and the real value ofthe quantity of symbols occupied by the data channel or sending the datachannel to the network device based on the real value of the index ofthe starting symbol of the data channel and the real value of thequantity of symbols occupied by the data channel.

In this implementation, an indicated slot boundary is used as thereference position. By comparing a configuration value of the index ofthe starting symbol of the PDCCH with the configuration value of theindex of the starting symbol of the data channel, the real value of theindex of the starting symbol of the data channel and the real value ofthe quantity of symbols occupied by the data channel can be accuratelydetermined. Therefore, data is received accurately. When the PDCCH islocated before the configuration value of the index of the startingsymbol of the data channel, the real value of the index of the startingsymbol of the data channel is determined according to the rule, so thatit can be ensured that the data channel is closely after the PDCCH orthe data channel and the PDCCH have a same starting symbol, therebyreducing latency. According to this rule, the real value of the quantityof occupied symbols can ensure that data scheduling is limited withinone slot and does not cross a slot boundary, thereby reducingcommunication complexity.

According to a second aspect, a communication method is provided. Themethod includes: sending first indication information to a terminaldevice, where the first indication information is used to indicate areference position of a starting symbol of a data channel; sending aphysical downlink control channel PDCCH to the terminal device; andsending the data channel to the terminal device or receiving a datachannel from the terminal device.

With reference to the second aspect, in a first possible implementation,the reference position includes any one of the following: a slotboundary, a starting symbol of a control resource set, an ending symbolof the control resource set, a starting symbol of a control area, anending symbol of the control area, a starting symbol of the PDCCH, andan ending symbol of the PDCCH.

With reference to the second aspect or the first possible implementationof the second aspect, in a second possible implementation, the firstindication information is associated with the terminal device, or thefirst indication information is associated with a format of downlinkcontrol information.

With reference to the second aspect, the first possible implementationof the second aspect, or the second possible implementation of thesecond aspect, in a third possible implementation, the method furtherincludes: sending higher layer signaling to the terminal device, wherethe higher layer signaling includes at least one set of an index of astarting symbol of a data channel and a quantity of symbols occupied bythe data channel.

With reference to the third possible implementation manner of the secondaspect, in a fourth possible implementation manner, when the higherlayer signaling includes one set of an index S1 of a starting symbol anda quantity L1 of occupied symbols, a configuration value S of the indexof the starting symbol of the data channel is equal to S1 and aconfiguration value L of the quantity of symbols occupied by the datachannel is equal to L1; or when the higher layer signaling includes atleast two sets of indexes of starting symbols and quantities of occupiedsymbols, a configuration value S of an index of a starting symbol thatis of a data channel and that is indicated by the PDCCH is equal to S2and a configuration value L of a quantity of occupied symbols is equalto L2, where the index S2 of the starting symbol and the quantity L2 ofoccupied symbols are one set of the at least two sets of the indexes ofthe starting symbols and the quantities of occupied symbols.

With reference to the fourth possible implementation of the secondaspect, in a fifth possible implementation, the reference position is aslot boundary; and when an index T of the starting symbol of the PDCCHis greater than or equal to the configuration value S of the index ofthe starting symbol of the data channel, a real value S(real) of theindex of the starting symbol of the data channel is equal to the index Tof the starting symbol of the PDCCH, and a real value L(real) of thequantity of symbols occupied by the data channel is equal to: theconfiguration value L of the quantity of symbols occupied by the datachannel, or a smaller value between the configuration value L of thequantity of symbols occupied by the data channel and a differencebetween a quantity of symbols included in one slot and S(real).

With reference to the fourth possible implementation of the secondaspect, in a sixth possible implementation, the reference position is aslot boundary; and when an index T of the starting symbol of the PDCCHis less than or equal to the configuration value S of the index of thestarting symbol of the data channel, a real value S(real) of the indexof the starting symbol of the data channel is equal to the configurationvalue S of the index of the starting symbol of the data channel, and areal value L(real) of the quantity of symbols occupied by the datachannel is equal to the configuration value L of the quantity of symbolsoccupied by the data channel.

With reference to the fourth possible implementation of the secondaspect, in a seventh possible implementation, the reference position isa slot boundary; and when an index T of the starting symbol of the PDCCHis less than or equal to the configuration value S of the index of thestarting symbol of the data channel, a real value S(real) of the indexof the starting symbol of the data channel is equal to the index T ofthe starting symbol of the PDCCH, and a real value L(real) of thequantity of symbols occupied by the data channel is equal to theconfiguration value L of the quantity of symbols occupied by the datachannel.

According to a third aspect, a communication method is provided. Themethod includes: receiving configuration value information of a startingsymbol of a data channel and configuration value information of aquantity of occupied symbols from a network device; determining a realvalue of the starting symbol of the data channel and a real value of thequantity of occupied symbols based on the configuration valueinformation of the starting symbol of the data channel and theconfiguration value information of the quantity of occupied symbols; andreceiving the data channel from the network device based on the realvalue of the starting symbol of the data channel and the real value ofthe quantity of occupied symbols or sending the data channel to thenetwork device based on the real value of the starting symbol of thedata channel and the real value of the quantity of occupied symbols.

In this aspect, the real value of the starting symbol of the datachannel and the real value of the quantity of occupied symbols areaccurately determined, so that the data channel can be sent or receivedat an accurate time domain position.

With reference to the third aspect, for another possible implementation,refer to the fourth possible implementation of the first aspect to thesixth possible implementation of the first aspect. Details are notdescribed herein again.

According to a fourth aspect, a communication method is provided. Themethod includes: sending configuration value information of a startingsymbol of a data channel and configuration value information of aquantity of occupied symbols to a terminal device; and sending the datachannel to the terminal device or receiving a data channel from theterminal device.

With reference to the fourth aspect, for another possibleimplementation, refer to the fourth possible implementation of thesecond aspect to the sixth possible implementation of the second aspect.Details are not described herein again.

According to a fifth aspect, a communication method is provided. Themethod includes: receiving a frequency domain resource indication value(RIV) of a data channel from a network device, where the RIV is used toindicate a frequency domain resource position of the data channel, theRIV is related to a quantity

N_(BWP)^(RGB)

of resource block groups (RBGs) in a bandwidth part (BWP), and

N_(BWP)^(RBG)

is related to a quantity

N_(BWP)^(size)

of RBs included in the BWP and an RBG size P; determining a frequencydomain resource position of the data channel based on the RIV; andsending the data channel to the network device on the frequency domainresource or receiving a data channel from the network device on thefrequency domain resource.

In this aspect, the frequency domain resource indication value of thedata channel is related to the quantity of resource block groups in thebandwidth part, so that bit overheads for sending the frequency domainresource indication value can be reduced.

With reference to the fifth aspect, in a first possible implementation,the method further includes: receiving first indication information fromthe network device, where the first indication information is used toindicate one of at least two RBG sizes corresponding to a range of thequantity of RBs included in the BWP.

In this implementation, the range of the quantity of RBs included in theBWP corresponds to the at least two RBG sizes. A corresponding RBG sizemay be determined based on a specific range of the quantity of RBsincluded in the BWP.

With reference to the fifth aspect or the first possible implementationof the fifth aspect, in a second possible implementation, when thequantity of RBs included in the BWP ranges from 1 to 36, twocorresponding RBG sizes are 4 and 8; when the quantity of RBs includedin the BWP ranges from 37 to 72, two corresponding RBG sizes are 8 and16; when the quantity of RBs included in the BWP ranges from 73 to 144,two corresponding RBG sizes are 16 and 32; or when the quantity of RBsincluded in the BWP ranges from 145 to 275, two corresponding RBG sizesare 32 and 32.

Alternatively, when the quantity of RBs included in the BWP ranges from1 to 36, two corresponding RBG sizes are 2 and 4; when the quantity ofRBs included in the BWP ranges from 37 to 72, two corresponding RBGsizes are 4 and 8; when the quantity of RBs included in the BWP rangesfrom 73 to 144, two corresponding RBG sizes are 8 and 16; or when thequantity of RBs included in the BWP ranges from 145 to 275, twocorresponding RBG sizes are 16 and 16.

With reference to the fifth aspect or the first possible implementationof the fifth aspect, in a third possible implementation, P is a size ofa first RBG corresponding to the range of the quantity of RBs includedin the BWP.

In this implementation, it is specified that the range of the quantityof RBs included in the BWP corresponds to a first configured RBG size.For example, the first RBG size may be an RBG size with a larger valuebetween or a largest value among the at least two RBG sizescorresponding to the range of the quantity of RBs included in the BWP.Therefore, a frequency domain resource indication value is reduced, andbit overheads for indicating a frequency domain resource are reduced.

With reference to the fifth aspect, in a fourth possible implementation,a range of a quantity of RBs included in each BWP corresponds to one RBGsize.

In this implementation, a range of a quantity of RBs included in eachBWP corresponds to one RBG size. There is no need to set the range ofthe quantity of RBs included in each BWP to corresponding to a pluralityof RBG sizes, and one RBG size corresponding to the range of thequantity of RBs included in each BWP may be set relatively large.Therefore, the frequency domain resource indication value is reduced,and bit overheads for indicating a frequency domain resource arereduced. In addition, the RBG size may be directly determined based onthe range of the quantity of RBs included in the BWP, and no additionalindication information is required, thereby reducing signalingoverheads.

With reference to the fifth aspect, in a fifth possible implementation,P is a fixed value predefined in a protocol.

In this implementation, P is a fixed value, for example, fixed to 8, 16,or 32, and is irrelevant to the range of the quantity of RBs included ineach BWP. Therefore, implementation is simple.

With reference to the fifth aspect, in a sixth possible implementation,the method further includes: receiving P from the network device.

In this implementation, P may be set by the network device, and thenetwork device notifies a terminal device of determined P. Therefore,implementation is flexible.

With reference to the fifth aspect, the first possible implementation ofthe fifth aspect, the second possible implementation of the fifthaspect, the third possible implementation of the fifth aspect, thefourth possible implementation of the fifth aspect, the fifth possibleimplementation of the fifth aspect, or the sixth possible implementationof the fifth aspect, in a seventh possible implementation, the RIV isdetermined by using the following formula:

$\begin{array}{l}{\text{if}\left( {\text{L}_{RBG} - 1} \right) \leq \left( \left\lfloor {N_{BWP}^{RBG}/2} \right\rfloor \right),\text{then}} \\{RIV = N_{BWP}^{RBG}\left( {\text{L}_{RBG} - 1} \right) + RBG_{Start}} \\\text{else} \\{\quad RIV = N_{BWP}^{RBG}\left( {N_{BWP}^{RBG} - \text{L}_{RBG} + 1} \right) + \left( {N_{BWP}^{RBG} - 1 - RBG_{Start}} \right)}\end{array}$

where L_(RBG) represents a quantity of RBGs occupied by a frequencydomain of a data channel, and

L_(RBG) ≥ 1; N_(BWP)^(RBG) = ⌈N_(BWP)^(size)/P⌉

1; = , and represents a quantity of RBGs in a

N_(BWP)^(size)

is a quantity of RBs included in the BWP, and P is an RBG size, namely,a quantity of RBs included in one RBG; RBG_(Start) is a starting RBGnumber of the frequency domain of the data channel; and

L_(RBG) ≤ N_(BWP)^(RBG) − RBG_(Start).

.

In this implementation, the frequency domain resource indication valueof the data channel is related to the quantity of resource block groupsin the bandwidth part, so that bit overheads for sending the frequencydomain resource indication value can be reduced.

According to a sixth aspect, a communication method is provided. Themethod includes: determining a frequency domain resource indicationvalue RIV of a data channel, where the RIV is used to indicate afrequency domain resource position of the data channel, the RIV isrelated to a quantity

N_(BWP)^(RBG)

of resource block groups RBGs in a bandwidth part BWP, and

N_(BWP)^(RBG)

is related to a quantity

N_(BWP)^(size)

of RBs included in the BWP and an RBG size P; sending the RIV to aterminal device; and sending the data channel to the terminal device atthe frequency domain resource position indicated by the RIV or receivinga data channel from the terminal device at the frequency domain resourceposition.

With reference to the sixth aspect, in a first possible implementation,the method further includes: sending first indication information to theterminal device, where the first indication information is used toindicate one of at least two RBG sizes corresponding to a range of thequantity of RBs included in the BWP.

With reference to the sixth aspect or the first possible implementationof the sixth aspect, in a second possible implementation, when thequantity of RBs included in the BWP ranges from 1 to 36, twocorresponding RBG sizes are 4 and 8; when the quantity of RBs includedin the BWP ranges from 37 to 72, two corresponding RBG sizes are 8 and16; when the quantity of RBs included in the BWP ranges from 73 to 144,two corresponding RBG sizes are 16 and 32; or when the quantity of RBsincluded in the BWP ranges from 145 to 275, two corresponding RBG sizesare 32 and 32.

Alternatively, when the quantity of RBs included in the BWP ranges from1 to 36, two corresponding RBG sizes are 2 and 4; when the quantity ofRBs included in the BWP ranges from 37 to 72, two corresponding RBGsizes are 4 and 8; when the quantity of RBs included in the BWP rangesfrom 73 to 144, two corresponding RBG sizes are 8 and 16; or when thequantity of RBs included in the BWP ranges from 145 to 275, twocorresponding RBG sizes are 16 and 16.

With reference to the sixth aspect or the first possible implementationof the sixth aspect, in a third possible implementation, P is a size ofa first RBG corresponding to the range of the quantity of RBs includedin the BWP.

With reference to the sixth aspect, in a fourth possible implementation,a range of a quantity of RBs included in each BWP corresponds to one RBGsize.

With reference to the sixth aspect, in a fifth possible implementation,P is a fixed value predefined in a protocol.

With reference to the sixth aspect, in a sixth possible implementation,the method further includes: sending P to the terminal device.

With reference to the sixth aspect, the first possible implementation ofthe sixth aspect, the second possible implementation of the sixthaspect, the third possible implementation of the sixth aspect, thefourth possible implementation of the sixth aspect, the fifth possibleimplementation of the sixth aspect, or the sixth possible implementationof the sixth aspect, in a seventh possible implementation, the RIV isdetermined by using the following formula:

$\begin{matrix}{\left( {\text{if}\left( {\text{L}_{RBG} - 1} \right) \leq \left\lfloor {N_{BWP}^{RBG}/2} \right\rfloor} \right),\,\text{then}} \\{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, RIV = N_{BWP}^{RBG}\left( {L_{RBG} - 1} \right) + RBG_{Start}} \\\text{else} \\{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, RIV = N_{BWP}^{RBG}\left( {N_{BWP}^{RBG} - L_{RBG} + 1} \right) + \left( {N_{BWP}^{RPG} - 1 - RBG_{Start}} \right)}\end{matrix}$

where L_(RBG) represents a quantity of RBGs occupied by a frequencydomain of a data channel, and

L_(RBG) ≥ 1; N_(BWP)^(RBG) = ⌈N_(BWP)^(size)/P⌉,

, and represents a quantity of RBGs in a BWP;

N_(BWP)^(size)

is a quantity of RBs included in the BWP, and P is an RBG size, namely,a quantity of RBs included in one RBG; RBG_(Start) is a starting RBGnumber of the frequency domain of the data channel; and

L_(RBG) ≤ N_(BWP)^(RBG) − RBG_(start)

.

According to a seventh aspect, a communications apparatus is provided,and can implement the communication method in the first aspect, thethird aspect, or the fifth aspect. For example, the communicationsapparatus may be a chip (such as a baseband chip or a communicationschip) or a terminal device. The foregoing method may be implemented byusing software, hardware, or hardware executing corresponding software.

In a possible implementation, a structure of the communicationsapparatus includes a processor and a memory. The processor is configuredto support the apparatus in performing a corresponding function in theforegoing communication method. The memory is configured to couple tothe processor, and the memory stores a necessary program (instruction)and/or necessary data of the apparatus. Optionally, the communicationsapparatus may further include a communications interface, configured tosupport communication between the apparatus and another network element.

In another possible implementation, the communications apparatus mayinclude a unit or a module for performing a corresponding action in theforegoing method.

In still another possible implementation, a processor and a transceiverapparatus are included. The processor is coupled to the transceiverapparatus. The processor is configured to execute a computer program orinstruction, to control the transceiver apparatus to send and receiveinformation; and when the processor executes the computer program orinstruction, the processor is further configured to implement theforegoing method. The transceiver apparatus may be a transceiver, atransceiver circuit, or an input/output interface. When thecommunications apparatus is a chip, the transceiver apparatus is atransceiver circuit or an input/output interface.

When the communications apparatus is a chip, a sending unit may be anoutput unit, for example, an output circuit or a communicationsinterface; and a receiving unit may be an input unit, for example, aninput circuit or a communications interface. When the communicationsapparatus is a network device, a sending unit may be a transmitter or atransmitter machine, and a receiving unit may be a receiver or areceiver machine.

According to an eighth aspect, a communications apparatus is provided,and can implement the communication method in the second aspect, thefourth aspect, or the sixth aspect. For example, the communicationsapparatus may be a chip (such as a baseband chip or a communicationschip) or a network device. The foregoing method may be implemented byusing software, hardware, or hardware executing corresponding software.

In a possible implementation, a structure of the communicationsapparatus includes a processor and a memory. The processor is configuredto support the apparatus in performing a corresponding function in theforegoing communication method. The memory is configured to couple tothe processor, and the memory stores a necessary program (instruction)and necessary data of the apparatus. Optionally, the communicationsapparatus may further include a communications interface, configured tosupport communication between the apparatus and another network element.

In another possible implementation, the communications apparatus mayinclude a unit or a module for performing a corresponding action in theforegoing method.

In still another possible implementation, a processor and a transceiverapparatus are included. The processor is coupled to the transceiverapparatus. The processor is configured to execute a computer program orinstruction, to control the transceiver apparatus to send and receiveinformation; and when the processor executes the computer program orinstruction, the processor is further configured to implement theforegoing method. The transceiver apparatus may be a transceiver, atransceiver circuit, or an input/output interface. When thecommunications apparatus is a chip, the transceiver apparatus is atransceiver circuit or an input/output interface.

When the communications apparatus is a chip, a receiving unit may be aninput unit, for example, an input circuit or a communications interface;and a sending unit may be an output unit, for example, an output circuitor a communications interface. When the communications apparatus is aterminal device, a receiving unit may be a receiver (which may also bereferred to as a receiver machine), and a sending unit may be atransmitter (which may also be referred to as a transmitter machine).

According to a ninth aspect, a computer-readable storage medium isprovided. The computer-readable storage medium stores a computer programor instruction. When the computer program or instruction is executed,the methods in the foregoing aspects are implemented.

According to a tenth aspect, a computer program product including aninstruction is provided. When the instruction is run on a computer, thecomputer is enabled to perform the method according to any one of theforegoing aspects.

BRIEF DESCRIPTION OF THE DRAWINGS

To describe technical solutions in embodiments or the background of thepresent invention more clearly, the following describes the accompanyingdrawings required for describing the embodiments or the background ofthe present invention.

FIG. 1 is a schematic diagram of potential occasions on which a URLLCservice may be scheduled in a slot;

FIG. 2 is a schematic diagram of a communications system according to anembodiment of this application;

FIG. 3 is a schematic interaction flowchart of a communication methodaccording to an embodiment of this application;

FIG. 4 is a schematic interaction flowchart of another communicationmethod according to an embodiment of this application;

FIG. 5 is a schematic interaction flowchart of still anothercommunication method according to an embodiment of this application;

FIG. 6 is a schematic structural diagram of a communications apparatusaccording to an embodiment of this application;

FIG. 7 is a schematic structural diagram of another communicationsapparatus according to an embodiment of this application;

FIG. 8 is a schematic structural diagram of still another communicationsapparatus according to an embodiment of this application;

FIG. 9 is a schematic structural diagram of still another communicationsapparatus according to an embodiment of this application;

FIG. 10 is a schematic structural diagram of still anothercommunications apparatus according to an embodiment of this application;

FIG. 11 is a schematic structural diagram of still anothercommunications apparatus according to an embodiment of this application;

FIG. 12 is a simplified schematic structural diagram of a terminaldevice according to an embodiment of this application; and

FIG. 13 is a simplified schematic structural diagram of a network deviceaccording to an embodiment of this application.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The following describes embodiments of the present invention withreference to the accompanying drawings in the embodiments of the presentinvention.

FIG. 2 is a schematic diagram of a communications system according tothis application. The communications system may include at least onenetwork device 100 (only one network device is shown) and one or moreterminal devices 200 connected to the network device 100.

The network device 100 may be a device that can communicate with theterminal device 200. The network device 100 may be any device with awireless transceiver function, and includes but is not limited to a basestation NodeB, an evolved NodeB (eNodeB), a base station in a fifthgeneration (5G) communications system, a base station or network devicein a future communications system, an access node in a Wi-Fi system, awireless relay node, a wireless backhaul node, and the like. The networkdevice 100 may alternatively be a radio controller in a cloud radioaccess network (CRAN) scenario. The network device 100 may alternativelybe a small cell, a transmission node (TRP), or the like. A specifictechnology and a specific device form that are used by the networkdevice are not limited in the embodiments of this application.

The terminal device 200 is a device having a wireless transceiverfunction, may be deployed on land, and includes an indoor device, anoutdoor device, a handheld device, a wearable device, or avehicle-mounted device; or may be deployed on a water surface, forexample, on a ship; or may be deployed in the air, for example, on aplane, a balloon, or a satellite. The terminal device may be a mobilephone, a tablet computer (Pad), a computer having a wireless transceiverfunction, a virtual reality (VR) terminal device, an augmented reality(AR) terminal device, a wireless terminal in industrial control, awireless terminal in self driving, a wireless terminal in a telemedicine(remote medical), a wireless terminal in a smart grid, a wirelessterminal in transportation safety, a wireless terminal in a smart city,a wireless terminal in a smart home, and the like. An applicationscenario is not limited in the embodiments of this application. Theterminal device may sometimes be referred to as user equipment (UE), anaccess terminal device, a UE unit, a mobile station, a mobile console, aremote station, a remote terminal device, a mobile device, a terminal, awireless communications device, a UE agent, a UE apparatus, or the like.

It should be noted that the terms “system” and “network” may be usedinterchangeably in the embodiments of the present invention. “Aplurality of” means two or more. In view of this, “a plurality of” mayalso be understood as “at least two” in the embodiments of the presentinvention. The term “and/or” describes an association relationship ofassociated objects and represents that three relationships may exist.For example, A and/or B may represent the following three cases: Only Aexists, both A and B exist, and only B exists. In addition, thecharacter “/” generally represents an “or” relationship between theassociated objects.

This application provides a communication method and a communicationsapparatus. A reference position of a starting symbol of a data channelis flexibly indicated by using indication information, so that accuratereceiving and sending of the data channel can be ensured, and a sendingoccasion of a PDCCH may not be limited.

FIG. 3 is a schematic interaction flowchart of a communication methodaccording to an embodiment of this application. The method may includethe following steps.

S101. A network device sends first indication information to a terminaldevice, where the first indication information is used to indicate areference position of a starting symbol of a data channel; and theterminal device receives the first indication information.

S102. The network device sends a PDCCH to the terminal device; and theterminal device receives the PDCCH.

S103 a. The network device sends a data channel to the terminal devicebased on the first indication information and the PDCCH; and theterminal device receives the data channel.

S103 b. The terminal device sends a data channel to the network devicebased on the first indication information and the PDCCH; and the networkdevice receives the data channel.

The network device sends the PDCCH. The PDCCH includes time domainresource indication information, and may further include frequencydomain resource indication information, a modulation and coding scheme(MCS) used for communication, and the like. This embodiment mainlyrelates to indication of a time domain resource. The time domainresource indication information is used to indicate an index, in a firsttime domain resource set, of a first time domain resource occupied by aphysical downlink shared channel (PDSCH) or a physical uplink sharedchannel (PUSCH).

A time domain position of data may be indicated by using an SLIV.Specifically, a start position may be an index of the starting symbol ofthe data channel, and a length indicator value may be a quantity ofsymbols occupied by the data channel. The first time domain resource setincludes indexes of starting symbols of one or more groups of datachannels and a quantity of symbols occupied by the data channel. Thenetwork device may send higher layer signaling, to preconfigure thefirst time domain resource set for the terminal device. A symbol in thisapplication may also be referred to as a time-domain symbol. Thetime-domain symbol herein may be an orthogonal frequency divisionmultiplexing (OFDM) symbol, or may be a discrete Fourier transformspread orthogonal frequency division multiplexing (DFTS-OFDM) symbol.

Downlink data is used as an example. First, a table (where a quantity nof rows in the table is less than or equal to 16) is configured by usinghigher layer signaling, and the table includes the first time domainresource set. The higher layer signaling may be radio resource control(RRC) signaling, medium access control (MAC) layer signaling, or thelike, as shown in Table 1 below. Table 1 shows examples of the firsttime domain resource set.

Table 1 Index (start, length) O SLIV 1 ... ... n SLIV n

In Table 1, start is an absolute value of the index of the startingsymbol of a time domain (for example, in a slot) of the data channel,and length is an absolute value of the quantity of symbols occupied bythe data channel. Start and length may be calculated by using a formula,to obtain the SLIV. Each SLIV may correspond to one index.

For example, assuming that the starting symbol of the data channel usesa slot boundary as the reference position, the SLIV may be obtained byusing the following formula 1:

$\begin{array}{l}{\text{if}^{{({L - 1})} \leq 7},\text{then}} \\{SLIV = 14 \cdot \left( {L - 1} \right) + S} \\\text{else} \\{SLIV = 14 \cdot \left( {14 - L + 1} \right) + \left( {14 - 1 - S} \right)} \\\text{where}^{0 < L \leq 14 - S}\end{array}$

The network device further sends the PDCCH to the terminal device. Thetime domain resource indication information indicated by the PDCCH mayinclude an index in Table 1, and the index is used to indicate a usedSLIV, so that the terminal device can derive start and length based onthe SLIV.

As shown in Table 1, a time domain resource table with a limited size isconfigured only by using the higher layer signaling, to indicate startand length indicator values of all possible time domain resources.Currently, a maximum size of the table is 16, that is, a maximum of 16combinations of starting symbols and lengths can be configured. In thiscase, if the reference position of the starting symbol of the datachannel is constantly a slot boundary, it is equivalent to that in oneslot, there are a maximum of 16 possible combinations of startingsymbols and lengths for data scheduling. However, for a URLLC service,because a latency requirement is relatively high, the PDCCH may be senton any symbol in a slot, and a length of scheduled data is relativelyflexible. Therefore, when a PDCCH is sent, time domain resources of aplurality of or all data channels configured by the network device arelocated before a time domain resource on which the PDCCH is sent.Consequently, the terminal device needs to buffer all received databefore receiving the PDCCH, in which case, a buffer of the terminaldevice increases and power consumption of the terminal device increases.Therefore, determining the reference position of the starting symbol isvery important.

In this embodiment, in S101, the network device sends the firstindication information to the terminal device, where the firstindication information is used to indicate the reference position of thestarting symbol S of the data channel. The reference position includesany one of the following: a slot boundary, a starting symbol of acontrol resource set (CORESET), an ending symbol of the control resourceset, a starting symbol of a control area, an ending symbol of thecontrol area, a starting symbol of the PDCCH, and an ending symbol ofthe PDCCH. The CORESET is a set of resources including one or morePDCCHs, and the control area is a set of resources including a PDCCH,and may include one or more CORESETs. The first indication informationmay be carried in the higher layer signaling, for example, RRC signalingor MAC signaling, or carried in physical layer dynamic signaling, forexample, a PDCCH.

The reference position indicating the starting symbol may be selectedbased on different application scenarios. For example, if the terminaldevice is scheduled to perform an emergency service or a service with arelatively high transmission reliability requirement, it may beindicated that the reference position of the starting symbol is astarting symbol of the PDCCH, an ending symbol of the PDCCH, a startingsymbol of a control resource set, an ending symbol of the controlresource set, a starting symbol of a control area, or an ending symbolof the control area, so that the data channel can be prevented fromappearing in front of a control channel, an amount of data buffered bythe terminal device can be reduced, and power consumption of theterminal device can be reduced. If the terminal device is scheduled toperform a service with a relatively low latency requirement, it may beindicated that a slot boundary is used as the reference position, sothat decrease of complexity of parsing PDCCH indication information bythe terminal device can be ensured. The data channel may be received byusing the slot boundary as the reference position each time, so thatimplementation complexity of the terminal device can be reduced.Further, in an implementation, the first indication information may beassociated with the terminal device. For example, different referencepositions of starting symbols of data channels are indicated fordifferent terminal devices.

For example, a starting symbol of the PDCCH, an ending symbol of thePDCCH, a starting symbol of a control resource set, an ending symbol ofthe control resource set, a starting symbol of a control area, or anending symbol of the control area is indicated to a terminal device thathas an emergency service transmission requirement or a relatively hightransmission reliability requirement, to serve as the reference positionof the starting symbol of the data channel, so that the data channel canbe prevented from appearing in front of a control channel, an amount ofdata buffered by the terminal device can be reduced, and powerconsumption of the terminal device can be reduced. A slot boundary isindicated to terminal devices that have a relatively low service latencyrequirement, to serve as the reference position, so that decrease ofcomplexity of parsing PDCCH indication information by the terminaldevice can be ensured. The data channel may be received by using theslot boundary as the reference position each time, so thatimplementation complexity of the terminal device can be reduced.

In another implementation, the first indication information may beassociated with a format of downlink control information. For example,different reference positions of starting symbols are configured fordifferent DCI formats.

For example, resources can also be properly used by configuringdifferent reference positions for different DCI formats. For example, astarting symbol of the PDCCH, an ending symbol of the PDCCH, a startingsymbol of a control resource set, an ending symbol of the controlresource set, a starting symbol of a control area, or an ending symbolof the control area is indicated to a DCI format that is used toschedule an emergency service, to serve as a reference position of astarting symbol, so that the data channel can be prevented fromappearing in front of a control channel, an amount of data buffered bythe terminal device can be reduced, and power consumption of theterminal device can be reduced. A slot boundary is indicated to DCIformats that have a relatively low latency requirement on a scheduledservice, to serve as the reference position, so that decrease ofcomplexity of parsing PDCCH indication information by the terminaldevice can be ensured. The data channel may be received by using theslot boundary as a reference position each time, so that implementationcomplexity of the terminal device can be reduced. A DCI format of theemergency service may be a DCI format for scheduling the URLLC service.For another example, a starting symbol of the PDCCH, an ending symbol ofthe PDCCH, a starting symbol of a control resource set, an ending symbolof the control resource set, a starting symbol of a control area, or anending symbol of the control area is indicated to compact downlinkcontrol information (compact DCI) or a DCI format with a relativelysmall quantity of bits, to serve as the reference position of thestarting symbol. Further, as described above, the time domain resourceset may be one row, to be specific, the higher layer signaling includesa set of an index S1 of a starting symbol and a quantity L1 of occupiedsymbols. To reduce bit overheads of control information carried on thePDCCH, the PDCCH may not include indication information of the timedomain, and the terminal device sends the data channel to the networkdevice by using, by default, the set of the index S1 of the startingsymbol and the quantity L1 of occupied symbols that are configured inthe higher layer signaling, or demodulates and decodes the received datachannel. Alternatively, the PDCCH may include one bit, used to indicatean index of the SLIV. Regardless of whether the PDCCH performsindication, if the time domain resource set includes only one set of theindex S1 of the starting symbol and the quantity L1 of occupied symbols,the terminal device may determine that a configuration value S of theindex of the starting symbol of the data channel is equal to S1 and aconfiguration value L of the quantity of symbols occupied by the datachannel is equal to L1.

When the higher layer signaling includes at least two sets of indexes ofstarting symbols and quantities of occupied symbols, an index of astarting symbol indicated by the PDCCH is S2, and a quantity of occupiedsymbols is L2, the terminal device may determine that a configurationvalue S of an index of the starting symbol of the data channel is equalto S2 and a configuration value L of the quantity of symbols occupied bythe data channel is equal to L2, where S2 and L2 are one set of the atleast two sets of the indexes of the starting symbols and the quantitiesof occupied symbols.

Further, when the reference position is a slot boundary, because aservice such as a low-latency and high-reliability service requiresrelatively frequent blind detection on the PDCCH, and the PDCCH may besent at many occasions, the starting symbol or the ending symbol of thePDCCH, the starting symbol or the ending symbol of the CORESET, or thestarting symbol or the ending symbol of the control area may be beforethe starting symbol of the data channel, or may be after the startingsymbol of the data channel. Therefore, a real value S(real) of the indexof the starting symbol of the data channel and a real value L(real) ofthe quantity of symbols occupied by the data channel may be determinedbased on a value relationship between the index T of the starting symbolof the PDCCH and the configuration value S of the index of the startingsymbol of the data channel.

Specifically, in an implementation, when the reference position of thestarting symbol is a slot boundary, the network device may configurethat when the index T of the starting symbol or the ending symbol of thePDCCH, the starting symbol or the ending symbol of the CORESET, or thestarting symbol or the ending symbol of the control area is greater thanor equal to the configuration value S of the index of the startingsymbol of the data channel, the real value S(real) of the index of thestarting symbol of the data channel is equal to the index T of thestarting symbol of the PDCCH, and the real value L(real) of the quantityof symbols occupied by the data channel is equal to: the configurationvalue L of the quantity of symbols occupied by the data channel, or asmaller value between the configuration value L of the quantity ofsymbols occupied by the data channel and a difference between a quantityof symbols included in one slot and S(real). In other words, the networkdevice sends the PDCCH to indicate the configuration value of the indexof the starting symbol of the data channel and the configuration valueof the quantity of occupied symbols, and sends the data channel to theterminal device based on the real value of the index of the startingsymbol of the data channel and the real value of the quantity ofoccupied symbols, or receives a data channel from the terminal devicebased on the real value of the index of the starting symbol of the datachannel and the real value of the quantity of occupied symbols.

The terminal device may determine, based on the reference position ofthe starting symbol and the PDCCH, that the real value S(real) of theindex of the starting symbol of the data channel is the index T of thestarting symbol or the ending symbol of the PDCCH, the starting symbolor the ending symbol of the CORESET, or the starting symbol or theending symbol of the control area; and determine that the real valueL(real) of the quantity of symbols occupied by the data channel is: theconfiguration value L of the quantity of symbols occupied by the datachannel, or a smaller value between the configuration value L of thequantity of symbols occupied by the data channel and a differencebetween a quantity of symbols included in one slot and S(real). That is,L(real) may be the configuration value L, or may be determined based onS(real): a smaller value between the configuration value L of thequantity of symbols occupied by the data channel and a differencebetween the quantity of symbols included in one slot and S(real). Inaddition, the terminal device demodulates and decodes the data channelbased on the real value of the index of the starting symbol of the datachannel and the real value of the quantity of symbols occupied by thedata channel.

When the PDCCH is located after the configuration value of the index ofthe starting symbol of the data channel, the real value of the index ofthe starting symbol of the data channel is determined according to therule, so that it can be ensured that the data channel is always afterthe PDCCH, thereby reducing an amount of data buffered by the terminaldevice, and reducing power consumption of the terminal device. Accordingto this rule, the real value of the quantity of occupied symbols canensure that data scheduling is limited within one slot and does notcross a slot boundary, thereby reducing communication complexity.

In another implementation, when the reference position of the startingsymbol is a slot boundary, the network device may configure that whenthe index T of the starting symbol or the ending symbol of the PDCCH,the starting symbol or the ending symbol of the CORESET, or the startingsymbol or the ending symbol of the control area is less than or equal tothe configuration value S of the index of the starting symbol of thedata channel, the real value S(real) of the index of the starting symbolof the data channel is equal to the configuration value S of the indexof the starting symbol of the data channel, and the real value L(real)of the quantity of symbols occupied by the data channel is equal to theconfiguration value L of the quantity of symbols occupied by the datachannel.

The terminal device may determine, based on the reference position ofthe starting symbol and the PDCCH, that the real value S(real) of theindex of the starting symbol of the data channel is equal to theconfiguration value S of the index of the starting symbol of the datachannel, and the real value L(real) of the quantity of symbols occupiedby the data channel is equal to the configuration value L of thequantity of symbols occupied by the data channel; and demodulate anddecode the data channel based on the real value of the index of thestarting symbol of the data channel and the real value of the quantityof symbols occupied by the data channel.

When the PDCCH is located before the configuration value of the index ofthe starting symbol of the data channel, it is determined, according tothis rule, that the real value of the index of the starting symbol ofthe data channel and the real value of the quantity of symbols occupiedby the data channel are respectively equal to the configuration values,so that parsing complexity of the terminal device can be reduced.

In still another implementation, when the reference position of thestarting symbol is a slot boundary, the network device may configurethat when the index T of the starting symbol or the ending symbol of thePDCCH, the starting symbol or the ending symbol of the CORESET, or thestarting symbol or the ending symbol of the control area is less than orequal to the configuration value S of the index of the starting symbolof the data channel, the real value S(real) of the index of the startingsymbol of the data channel is equal to the index T of the startingsymbol or the ending symbol of the PDCCH, the starting symbol or theending symbol of the CORESET, or the starting symbol or the endingsymbol of the control area, and the real value L(real) of the quantityof symbols occupied by the data channel is equal to the configurationvalue L of the quantity of symbols occupied by the data channel.

The terminal device may determine, based on the reference position ofthe starting symbol and the PDCCH, that the real value S(real) of theindex of the starting symbol of the data channel is equal to the index Tof the starting symbol of the PDCCH, and the real value L(real) of thequantity of symbols occupied by the data channel is equal to theconfiguration value L of the quantity of symbols occupied by the datachannel; and demodulate and decode the data channel based on the realvalue of the index of the starting symbol of the data channel and thereal value of the quantity of symbols occupied by the data channel.

When the PDCCH is located before the configuration value of the index ofthe starting symbol of the data channel, the real value of the index ofthe starting symbol of the data channel is determined according to therule, so that it can be ensured that the data channel is closely afterthe PDCCH or the data channel and the PDCCH have a same starting symbol,thereby reducing latency. According to this rule, the real value of thequantity of occupied symbols can ensure that data scheduling is limitedwithin one slot and does not cross a slot boundary, thereby reducingcommunication complexity.

In foregoing implementation, an indicated slot boundary is used as thereference position. By comparing the configuration value of the index ofthe starting symbol of the PDCCH with the configuration value of theindex of the starting symbol of the data channel, the real value of theindex of the starting symbol of the data channel and the real value ofthe quantity of symbols occupied by the data channel can be accuratelydetermined. Therefore, the data channel is sent accurately, or thereceived data channel is demodulated and decoded.

According to the communication method provided in this embodiment ofthis application, the reference position of the starting symbol of thedata channel is flexibly indicated by using indication information, sothat accurate receiving and sending of the data channel can be ensured,and a sending occasion of the PDCCH may not be limited.

FIG. 4 is a schematic flowchart of another communication methodaccording to an embodiment of this application. The method may includethe following steps.

S201. A network device sends configuration value information of astarting symbol of a data channel and configuration value information ofa quantity of occupied symbols to a terminal device; and the terminaldevice receives the configuration value information.

S202. The terminal device determines a real value of the starting symbolof the data channel and a real value of the quantity of occupied symbolsbased on the configuration value information of the starting symbol ofthe data channel and the configuration value information of the quantityof occupied symbols.

S203 a. The network device sends the data channel to the terminal devicebased on the real value of the starting symbol of the data channel andthe real value of the quantity of occupied symbols; and the terminaldevice receives the data channel.

S203 b. The terminal device sends a data channel to the network devicebased on the real value of the starting symbol of the data channel andthe real value of the quantity of occupied symbols; and the networkdevice receives the data channel.

In this embodiment, the starting symbol of the data channel uses a slotboundary as the reference position. Because a service such as alow-latency and high-reliability service requires relatively frequentblind detection on a PDCCH, and the PDCCH may be sent at many occasions,a starting symbol or an ending symbol of the PDCCH, a starting symbol oran ending symbol of a CORESET, or a starting symbol or an ending symbolof a control area may be before the starting symbol of the data channel,or may be after the starting symbol of the data channel. Therefore,there may be a problem that the data channel exists before a controlchannel, and the terminal device needs to buffer data received beforethe PDCCH is received.

In this embodiment, the real value of the starting symbol of the datachannel and the real value of the quantity of occupied symbols need tobe determined based on the configuration value information of thestarting symbol that is of the data channel and that is indicated by thePDCCH, the configuration value information of the quantity of occupiedsymbols, and the reference position of the starting symbol.

First, in S201, the network device sends the configuration valueinformation of the starting symbol of the data channel and theconfiguration value information of the quantity of occupied symbols tothe terminal device. The configuration value information specificallyincludes an index of the starting symbol of the data channel and thequantity of occupied symbols.

Specifically, S201 includes: sending higher layer signaling to theterminal device, where the higher layer signaling includes at least oneset of the index of the starting symbol of the data channel and thequantity of symbols occupied by the data channel; and sending thephysical downlink control channel (PDCCH) to the terminal device, wherethe higher layer signaling and/or the PDCCH are/is configured toindicate a configuration value S of the index of the starting symbol ofthe data channel and a configuration value L of the quantity of symbolsoccupied by the data channel.

For example, the higher layer signaling includes a set of an index S1 ofa starting symbol and a quantity L1 of occupied symbols. To reduce bitoverheads of control information carried on the PDCCH, the PDCCH may notinclude indication information of the time domain, and the terminaldevice sends the data channel to the network device by using, bydefault, the set of the index S1 of the starting symbol and the quantityL1 of occupied symbols that are configured in the higher layersignaling, or demodulates and decodes the received data channel.Alternatively, the PDCCH may include one bit, used to indicate an indexof an SLIV. Regardless of whether the PDCCH performs indication, if atime domain resource set includes only one set of the index S1 of thestarting symbol and the quantity L1 of occupied symbols, the terminaldevice may determine that the configuration value S of the index of thestarting symbol of the data channel is equal to S1 and the configurationvalue L of the quantity of symbols occupied by the data channel is equalto L1.

When the higher layer signaling includes at least two sets of indexes ofstarting symbols and quantities of occupied symbols, an index of astarting symbol indicated by the PDCCH is S2, and a quantity of occupiedsymbols is L2, the terminal device may determine that the configurationvalue S of the index of the starting symbol of the data channel is equalto S2 and the configuration value L of the quantity of symbols occupiedby the data channel is equal to L2, where S2 and L2 are one set of theat least two sets of the indexes of the starting symbols and thequantities of occupied symbols.

Subsequently, after S201 or S202 a (to be specific, after the terminaldevice receives the data channel sent by the network device), theterminal device determines the real value of the starting symbol of thedata channel and the real value of the quantity of occupied symbolsbased on the configuration value information of the starting symbol ofthe data channel and the configuration value information of the quantityof occupied symbols. Alternatively, before S202 b (to be specific,before the terminal device sends the data channel to the networkdevice), the terminal device may determine the real value of thestarting symbol of the data channel and the real value of the quantityof occupied symbols.

Specifically, a real value S(real) of the index of the starting symbolof the data channel and a real value L(real) of the quantity of symbolsoccupied by the data channel may be determined based on a valuerelationship between an index T of a starting symbol of the PDCCH andthe configuration value S of the index of the starting symbol of thedata channel.

In an implementation, when the reference position of the starting symbolis a slot boundary, the network device may configure that when the indexT of the starting symbol or the ending symbol of the PDCCH, the startingsymbol or the ending symbol of the CORESET, or the starting symbol orthe ending symbol of the control area is greater than or equal to theconfiguration value S of the index of the starting symbol of the datachannel, the real value S(real) of the index of the starting symbol ofthe data channel is equal to the index T of the starting symbol of thePDCCH, and the real value L(real) of the quantity of symbols occupied bythe data channel is equal to: the configuration value L of the quantityof symbols occupied by the data channel, or a smaller value between theconfiguration value L of the quantity of symbols occupied by the datachannel and a difference between a quantity of symbols included in oneslot and S(real). In other words, the network device sends the PDCCH toindicate the configuration value of the index of the starting symbol ofthe data channel and the configuration value of the quantity of occupiedsymbols, and sends the data channel to the terminal device based on thereal value of the index of the starting symbol of the data channel andthe real value of the quantity of occupied symbols, or receives a datachannel from the terminal device based on the real value of the index ofthe starting symbol of the data channel and the real value of thequantity of occupied symbols.

In other words, the terminal device may determine, based on thereference position of the starting symbol and the PDCCH, that the realvalue S(real) of the index of the starting symbol of the data channel isthe index T of the starting symbol or the ending symbol of the PDCCH,the starting symbol or the ending symbol of the CORESET, or the startingsymbol or the ending symbol of the control area; and determine that thereal value L(real) of the quantity of symbols occupied by the datachannel is: the configuration value L of the quantity of symbolsoccupied by the data channel, or a smaller value between theconfiguration value L of the quantity of symbols occupied by the datachannel and a difference between a quantity of symbols included in oneslot and S(real). That is, L(real) may be the configuration value L, ormay be determined based on S(real): a smaller value between theconfiguration value L of the quantity of symbols occupied by the datachannel and a difference between the quantity of symbols included in oneslot and S(real). In addition, the terminal device demodulates anddecodes the data channel based on the real value of the index of thestarting symbol of the data channel and the real value of the quantityof symbols occupied by the data channel.

In another implementation, when the reference position of the startingsymbol is a slot boundary, the network device may configure that whenthe index T of the starting symbol or the ending symbol of the PDCCH,the starting symbol or the ending symbol of the CORESET, or the startingsymbol or the ending symbol of the control area is less than or equal tothe configuration value S of the index of the starting symbol of thedata channel, the real value S(real) of the index of the starting symbolof the data channel is equal to the configuration value S of the indexof the starting symbol of the data channel, and the real value L(real)of the quantity of symbols occupied by the data channel is equal to theconfiguration value L of the quantity of symbols occupied by the datachannel.

The terminal device may determine, based on the reference position ofthe starting symbol and the PDCCH, that the real value S(real) of theindex of the starting symbol of the data channel is equal to theconfiguration value S of the index of the starting symbol of the datachannel, and the real value L(real) of the quantity of symbols occupiedby the data channel is equal to the configuration value L of thequantity of symbols occupied by the data channel; and demodulate anddecode the data channel based on the real value of the index of thestarting symbol of the data channel and the real value of the quantityof symbols occupied by the data channel.

In still another implementation, when the reference position of thestarting symbol is a slot boundary, the network device may configurethat when the index T of the starting symbol or the ending symbol of thePDCCH, the starting symbol or the ending symbol of the CORESET, or thestarting symbol or the ending symbol of the control area is less than orequal to the configuration value S of the index of the starting symbolof the data channel, the real value S(real) of the index of the startingsymbol of the data channel is equal to the index T of the startingsymbol or the ending symbol of the PDCCH, the starting symbol or theending symbol of the CORESET, or the starting symbol or the endingsymbol of the control area, and the real value L(real) of the quantityof symbols occupied by the data channel is equal to the configurationvalue L of the quantity of symbols occupied by the data channel.

In this case, the terminal device may determine, based on the referenceposition of the starting symbol and the PDCCH, that the real valueS(real) of the index of the starting symbol of the data channel is equalto the index T of the starting symbol of the PDCCH, and the real valueL(real) of the quantity of symbols occupied by the data channel is equalto the configuration value L of the quantity of symbols occupied by thedata channel; and demodulate and decode the data channel based on thereal value of the index of the starting symbol of the data channel andthe real value of the quantity of symbols occupied by the data channel.

In the foregoing implementations, an indicated slot boundary is used asthe reference position. By comparing the configuration value of theindex of the starting symbol of the PDCCH with the configuration valueof the index of the starting symbol of the data channel, the real valueof the index of the starting symbol of the data channel and the realvalue of the quantity of symbols occupied by the data channel can beaccurately determined. Therefore, the data channel is sent accurately,or the received data channel is demodulated and decoded.

According to the communication method provided in this embodiment ofthis application, the network device sends the reference position of thestarting symbol, the configuration value information of the startingsymbol, and the configuration value information of the quantity ofoccupied symbols, so that the terminal device can accurately determinethe real value of the starting symbol of the data channel and the realvalue of the quantity of occupied symbols. In this way, the data channelcan be sent or received at an accurate time domain position.

In NR, a starting resource block (RB_(start)) and a quantity ( ^(L)_(RBs) ) of consecutive RBs in frequency domain are indicated by using aresource indication value (RIV). The RIV is related to a quantity

N_(BWP)^(size)

of resource blocks (RB) included in a downlink bandwidth part (BWP),^(L) _(RBs) , and RB_(start). If a frequency domain resource isindicated by using the RIV, a quantity of required bits is

⌈log₂(N_(BWP)^(size)(N_(BWP)^(size) + 1)/2)⌉

. If the BWP bandwidth is 100 RBs, 11 bits are required. In this case, arelatively large quantity of bits are required.

For a URLLC service that has a relatively high reliability requirement,reliability of a PDCCH also needs to be ensured. To improve reliabilityof a control channel, one method is to reduce a quantity of bits of thePDCCH. Therefore, an indicator field that can be compressed and that isof the PDCCH, for example, a frequency domain indicator field, needs tobe compressed.

Therefore, the embodiments of this application further provide stillanother communication method and communications apparatus. A frequencydomain resource indication value of a data channel is enabled to berelated to a quantity of resource block groups in a bandwidth part, sothat bit overheads for sending the frequency domain resource indicationvalue can be reduced, thereby improving reliability of the PDCCH.

FIG. 5 is a schematic flowchart of another communication methodaccording to an embodiment of this application. The method may includethe following steps.

S301. A network device determines a frequency domain RIV of a datachannel, where the RIV is used to indicate a frequency domain resourceposition of the data channel, the RIV is related to a quantity

N_(BWP)^(RBG)

of resource block groups (RBG) in a bandwidth part BWP, and

N_(BWP)^(RBG)

is related to a quantity

N_(BWP)^(size)

of RBs included in the BWP and an RBG size P.

S302. The network device sends the frequency domain RIV to a terminaldevice; and the terminal device receives the frequency domain RIV.

S303 a. The network device sends the data channel to the terminal deviceat a frequency domain resource position indicated by the frequencydomain RIV; and the terminal device receives the data channel at thefrequency domain resource position.

S303 b. The terminal device sends a data channel to the network deviceat the frequency domain resource position indicated by the frequencydomain RIV; and the network device receives the data channel at thefrequency domain resource position.

The network device sends a PDCCH to the terminal device. The PDCCHincludes indication information of a frequency domain resource, and mayfurther include indication information of a time domain resource, anMCS, and the like. This embodiment mainly relates to indication of thefrequency domain resource.

The network device first determines the frequency domain RIV. In thisembodiment, the RIV is related to the quantity

N_(BWP)^(RBG)

of RBGs in the BWP, and

N_(BWP)^(RBG)

is related to the quantity

N_(BWP)^(size)

of RBs included in the BWP and the size P of the RBG. That is, resourceallocation is performed at a granularity of an RBG. The size of the RBGmay be a quantity of RBs included in one RBG.

Specifically, the frequency domain RIV may be determined by using thefollowing formula 2:

$\begin{array}{l}{\text{if}\left( {\text{L}_{RBG} - 1} \right) \leq \left( \left\lfloor {N_{BWP}^{RBG}/2} \right\rfloor \right),\text{then}} \\{\quad\quad\quad\quad\quad\quad\quad\quad RIV = N_{BWP}^{RBG}\left( {\text{L}_{RBG} - 1} \right) + RBG_{Start}} \\\text{else} \\{RIV = N_{BWP}^{RBG}\left( {N_{BWP}^{RBG} - \text{L}_{RBG} + 1} \right) + \left( {N_{BWP}^{RBG} - 1 - RBG_{Start}} \right)}\end{array}$

where L_(RBG) represents a quantity of RBGs occupied by a frequencydomain of a data channel, and

L_(RBG) ≥ 1; N_(BWP)^(RBG) = ⌈N_(BWP)^(size)/P⌉

, and represents a quantity of RBGs in a BWP;

N_(BWP)^(size)

is a quantity of RBs included in the BWP, and P is an RBG size, namely,a quantity of RBs included in one RBG; RBG_(Start) is a starting RBGnumber of the frequency domain of the data channel; and

L_(RBG) ≤ N_(BWP)^(RBG) − RBG_(Start).

If the quantity of RBs included in the BWP is a value known to theterminal device,

N_(BWP)^(RBG)

is mainly related to the RBG size. Therefore, the RIV is also mainlyrelated to the RBG size.

The following describes in detail how to determine the RBG size.

In an implementation, the method further includes: sending firstindication information to the terminal device, where the firstindication information is used to indicate one of at least two RBG sizescorresponding to a range of the quantity of RBs included in the BWP.

For example, the network device determines the size P of the RBG basedon Table 2, and sends the first indication information to the terminaldevice to indicate a value of P. Table 2 below shows an example of acorrespondence between a range of a quantity of RBs included in a BWPand an RBG size.

Table 2 Range of the quantity of RBs included in the BWP RBG sizeConfiguration 1 Configuration 2 1 to 36 2 4 37 to 72 4 8 73 to 144 8 16145 to 275 16 16

As shown in Table 2, the range of the quantity of RBs included in eachBWP corresponds to two configurations of the RBG size. During specificscheduling, the network device determines, based on the range of thequantity of RBs included in the BWP, two configurations of the RBG sizethat correspond to the range of the quantity of RBs included in the BWP;and then determines, according to a scheduling policy, a configured RBGsize to be used for scheduling, and sends the indication information tothe terminal device to indicate a specific RBG size used for scheduling.For example, if the quantity of RBs included in the BWP is 100 RBs, itis determined that the quantity of RBs included in the BWP is within therange of 73 RBs to 144 RBs. Then, because a URLLC service is scheduled,and a relatively small quantity of bits that the frequency domainresource needs to indicate is required, a relatively large RBG may beselected, that is, RBG=16 is selected. Then, the network device sendsthe indication information to indicate that the RBG size used by theterminal device is the configuration 2. The terminal device maydetermine, based on the quantity of RBs included in the BWP and theindicated RBG size being the configuration 2, that the RBG size is 16RBs. The network device may send the first indication information to theterminal device, where the indication information includes at least onebit, to indicate the value of P.

The correspondence in Table 2 may be specified in a protocol, or may beconfigured for the terminal device by using system information or higherlayer signaling.

Further, in another implementation, to further reduce the quantity ofbits that is indicated by the frequency domain resource indication, theRBG size may be set to a larger value. For example, Table 3 shows anexample of another correspondence between a range of a quantity of RBsincluded in a BWP and an RBG size. The RBG size in Table 3 is increasedcompared with the configuration of the RBG size in Table 2.

Table 3 Range of the quantity of RBs included in the BWP RBG sizeConfiguration 1 Configuration 2 1 to 36 4 8 37 to 72 8 16 73 to 144 1632 145 to 275 32 32

The correspondence in Table 3 may be specified in a protocol, or may beconfigured for the terminal device by using system information or higherlayer signaling.

In the foregoing two implementations, the RBG size is configurable.Configuring a large RBG can effectively reduce the quantity of bits ofthe PDCCH (mainly the frequency domain resource indicator), therebyimproving PDCCH transmission reliability. In addition, when a servicepacket is relatively small, a relatively small RBG may be configured, toreduce a waste of frequency domain resources.

In still another implementation, P is a size of a first RBGcorresponding to the range of the quantity of RBs included in the BWP.The size of the first RBG may be defined according to a protocol.

For example, when scheduling data transmission, the network devicealways uses the RBG size in the configuration 1 or the configuration 2in Table 2 or Table 3. In this case, the network device may not need tosend the indication information to the terminal device, and the terminaldevice may determine the RBG size based on the range of the quantity ofRBs included in the BWP. For example, if the network device uses the RBGsize in the configuration 2 in Table 2, and the BWP includes 100 RBs, itis determined that the quantity of RBs included in the BWP is within therange of 73 RBs to 144 RBs, and it may be determined that the RBG sizeis 16 RBs.

In still another implementation, the range of the quantity of RBsincluded in each BWP corresponds to one RBG size.

Table 4 shows an example of still another correspondence between a rangeof a quantity of RBs included in a BWP and an RBG size. As shown inTable 4, a range of a quantity of RBs included in each BWP correspondsto one RBG size.

Table 4 Range of the quantity of RBs included in the BWP RBG sizeConfiguration 1 1 to 36 8 37 to 72 16 73 to 144 32 145 to 275 32

The correspondence in Table 4 may be configured by using higher layersignaling, or may be specified by using a protocol.

A range of a quantity of RBs included in each BWP corresponds to one RBGsize. There is no need to set the range of the quantity of RBs includedin each BWP to corresponding to a plurality of RBG sizes, and one RBGsize corresponding to the range of the quantity of RBs included in eachBWP may be set relatively large. Therefore, a frequency domain resourceindication value is reduced, and bit overheads for indicating afrequency domain resource are reduced. In addition, the RBG size may bedirectly determined based on the range of the quantity of RBs includedin the BWP, and no additional indication information is required,thereby reducing signaling overheads.

In addition, to further reduce the quantity of bits indicated by thefrequency domain resource, the RBG size may be configured to be slightlylarger. In this way, the quantity of bits of the PDCCH can beeffectively reduced, thereby improving PDCCH transmission reliability.In addition, an RBG size corresponding to the range of the quantity ofRBs included in each BWP is specified in a protocol in advance. Thenetwork device may not need to additionally notify the terminal deviceof the used RBG size, and the terminal device may determine thecorresponding RBG size based on the quantity of RBs included in the BWP,thereby reducing signaling overheads.

In still another implementation, P is a fixed value predefined in aprotocol, for example, fixed to 8, 16, or 32, and is irrelevant to therange of the quantity of RBs included in each BWP. Therefore,implementation is simple. The protocol may be a third generationpartnership project (3GPP) protocol.

For example, the protocol specifies that P=16. By using the foregoingresource allocation method and fixedly setting the RBG to a relativelylarge size, the quantity of bits of the PDCCH can be effectivelyreduced, thereby improving reliability of the PDCCH. In addition, a sizeof the RBG does not need to be notified of, so that signaling overheadscan be reduced. In addition, P may alternatively be 8, 32, or the like.

In still another implementation, the method further includes: sending Pto the terminal device.

The network device determines the RBG size P. P may be selected by thenetwork device. By sending configuration information to the terminaldevice, the terminal device is notified of the size P.

According to the foregoing resource allocation method, the RBG size isconfigurable. Therefore, a large RBG is configured to effectively reducethe quantity of bits of the PDCCH, thereby improving reliability of thePDCCH. In addition, when a service packet is relatively small, a smallRBG may be configured, to reduce a waste of resources.

According to the communication method provided in this embodiment ofthis application, the frequency domain resource indication value of thedata channel is enabled to be related to the quantity of resource blockgroups in the bandwidth part, so that bit overheads for sending thefrequency domain resource indication value can be reduced, therebyimproving reliability of the PDCCH.

The method in the embodiments of the present invention is describedabove in detail, and an apparatus in an embodiment of the presentinvention is provided below.

Based on a same concept as that of the communication method in theforegoing embodiments, as shown in FIG. 6 , an embodiment of thisapplication further provides a communications apparatus 1000. Thecommunications apparatus may be applied to the communication methodshown in FIG. 3 . The communications apparatus 1000 may be the terminaldevice 200 shown in FIG. 2 , or may be a component (for example, a chip)applied to the terminal device 200. The communications apparatus 1000includes a receiving unit 11 and a sending unit 12, and may furtherinclude a processing unit 13.

The receiving unit 11 is configured to receive first indicationinformation from a network device, where the first indicationinformation is used to indicate a reference position of a startingsymbol of a data channel.

The receiving unit 11 is further configured to receive a physicaldownlink control channel PDCCH from the network device.

The sending unit 12 is configured to send the data channel to thenetwork device based on the first indication information and the PDCCH.

The receiving unit 11 is further configured to receive the data channelfrom the network device based on the first indication information andthe PDCCH.

In an implementation, the receiving unit 11 is further configured toreceive higher layer signaling from the network device, where the higherlayer signaling includes at least one set of an index of a startingsymbol of a data channel and a quantity of symbols occupied by the datachannel.

In another implementation, the processing unit 13 is further configuredto: when the higher layer signaling includes one set of an index S1 of astarting symbol and a quantity L1 of occupied symbols, determine that aconfiguration value S of an index of the starting symbol of the datachannel is equal to S1 and a configuration value L of a quantity ofsymbols occupied by the data channel is equal to L1; or when the higherlayer signaling includes at least two sets of indexes of startingsymbols and quantities of occupied symbols, determine that aconfiguration value S of an index of a starting symbol indicated by thePDCCH is equal to S2 and a configuration value L of a quantity ofsymbols occupied by the data channel is equal to L2, where the index S2of the starting symbol and the quantity L2 of occupied symbols are oneset of the at least two sets of the indexes of the starting symbols andthe quantities of occupied symbols.

In still another implementation, the reference position is a slotboundary; and the processing unit 13 is further configured to: when anindex T of the starting symbol of the PDCCH is greater than or equal tothe configuration value S of the index of the starting symbol of thedata channel, determine that a real value S(real) of the index of thestarting symbol of the data channel is equal to the index T of thestarting symbol of the PDCCH, and a real value L(real) of the quantityof symbols occupied by the data channel is equal to: the configurationvalue L of the quantity of symbols occupied by the data channel, or asmaller value between the configuration value L of the quantity ofsymbols occupied by the data channel and a difference between a quantityof symbols included in one slot and S(real); and demodulate and decodethe data channel based on the real value of the index of the startingsymbol of the data channel and the real value of the quantity of symbolsoccupied by the data channel.

In still another implementation, the reference position is a slotboundary; and the processing unit 13 is further configured to: when anindex T of the starting symbol of the PDCCH is less than or equal to theconfiguration value S of the index of the starting symbol of the datachannel, determine that a real value S(real) of the index of thestarting symbol of the data channel is equal to the configuration valueS of the index of the starting symbol of the data channel, and a realvalue L(real) of the quantity of symbols occupied by the data channel isequal to the configuration value L of the quantity of symbols occupiedby the data channel; and demodulate and decode the data channel based onthe real value of the index of the starting symbol of the data channeland the real value of the quantity of symbols occupied by the datachannel.

In still another implementation, the reference position is a slotboundary; and the processing unit 13 is further configured to: when anindex T of the starting symbol of the PDCCH is less than or equal to theconfiguration value S of the index of the starting symbol of the datachannel, determine that a real value S(real) of the index of thestarting symbol of the data channel is equal to the index T of thestarting symbol of the PDCCH, and a real value L(real) of the quantityof symbols occupied by the data channel is equal to the configurationvalue L of the quantity of symbols occupied by the data channel; anddemodulate and decode the data channel based on the real value of theindex of the starting symbol of the data channel and the real value ofthe quantity of symbols occupied by the data channel.

For more detailed descriptions of the receiving unit 11, the sendingunit 12, and the processing unit 13, directly refer to relateddescriptions of the terminal device in the method embodiment shown inFIG. 3 , and details are not described herein again.

Based on a same concept as that of the communication method in theforegoing embodiments, as shown in FIG. 7 , an embodiment of thisapplication further provides a communications apparatus 2000. Thecommunications apparatus may be applied to the communication methodshown in FIG. 3 . The communications apparatus 2000 may be the networkdevice 100 shown in FIG. 2 , or may be a component (for example, a chip)applied to the network device 100. The communications apparatus 2000includes a sending unit 21 and a receiving unit 22.

The sending unit 21 is configured to send first indication informationto a terminal device, where the first indication information is used toindicate a reference position of a starting symbol of a data channel.

The sending unit 21 is further configured to send a physical downlinkcontrol channel PDCCH to the terminal device.

The sending unit 21 is configured to send the data channel to theterminal device.

The receiving unit 22 is configured to receive a data channel from theterminal device.

In an implementation, the sending unit 21 is further configured to sendhigher layer signaling to the terminal device, where the higher layersignaling includes at least one set of an index of a starting symbol ofa data channel and a quantity of symbols occupied by the data channel.

For more detailed descriptions of the sending unit 21 and the receivingunit 22, directly refer to related descriptions of the network device inthe method embodiment shown in FIG. 3 , and details are not describedherein again.

Based on a same concept as that of the communication method in theforegoing embodiments, as shown in FIG. 8 , an embodiment of thisapplication further provides a communications apparatus 3000. Thecommunications apparatus may be applied to the communication methodshown in FIG. 4 . The communications apparatus 3000 may be the terminaldevice 200 shown in FIG. 2 , or may be a component (for example, a chip)applied to the terminal device 200. The communications apparatus 3000includes a receiving unit 31, a processing unit 32, and a sending unit33.

The receiving unit 31 is configured to receive configuration valueinformation of a starting symbol of a data channel and configurationvalue information of a quantity of occupied symbols from a networkdevice.

The processing unit 32 is configured to determine a real value of thestarting symbol of the data channel and a real value of the quantity ofoccupied symbols based on the configuration value information of thestarting symbol of the data channel and the configuration valueinformation of the quantity of occupied symbols. The sending unit 33 isconfigured to send the data channel to the network device based on thereal value of the starting symbol of the data channel and the real valueof the quantity of occupied symbols.

The receiving unit 31 is further configured to receive the data channelfrom the network device based on the real value of the starting symbolof the data channel and the real value of the quantity of occupiedsymbols.

For more detailed descriptions of the receiving unit 31, the processingunit 32, and the sending unit 33, directly refer to related descriptionsof the terminal device in the method embodiment shown in FIG. 4 , anddetails are not described herein again.

Based on a same concept as that of the communication method in theforegoing embodiments, as shown in FIG. 9 , an embodiment of thisapplication further provides a communications apparatus 4000. Thecommunications apparatus may be applied to the communication methodshown in FIG. 4 . The communications apparatus 4000 may be the networkdevice 100 shown in FIG. 2 , or may be a component (for example, a chip)applied to the network device 100. The communications apparatus 4000includes a sending unit 41 and a receiving unit 42. The sending unit 41is configured to send configuration value information of a startingsymbol of a data channel and configuration value information of aquantity of occupied symbols to a terminal device.

The sending unit 41 is further configured to send the data channel tothe terminal device.

The receiving unit 42 is configured to receive a data channel from theterminal device.

In an implementation, the sending unit 41 is configured to send higherlayer signaling to the terminal device, where the higher layer signalingincludes at least one set of an index of the starting symbol of the datachannel and a quantity of symbols occupied by the data channel; and thesending unit 41 is further configured to send a physical downlinkcontrol channel PDCCH to the terminal device, where the higher layersignaling and/or the PDCCH are/is configured to indicate a configurationvalue S of the index of the starting symbol of the data channel and aconfiguration value L of the quantity of symbols occupied by the datachannel.

For more detailed descriptions of the sending unit 41 and the receivingunit 42, directly refer to related descriptions of the network device inthe method embodiment shown in FIG. 4 , and details are not describedherein again.

Based on a same concept as that of the communication method in theforegoing embodiments, as shown in FIG. 10 , an embodiment of thisapplication further provides a communications apparatus 5000. Thecommunications apparatus may be applied to the communication methodshown in FIG. 5 . The communications apparatus 5000 may be the terminaldevice 200 shown in FIG. 2 , or may be a component (for example, a chip)applied to the terminal device 200. The communications apparatus 5000includes a receiving unit 51, a processing unit 52, and a sending unit53.

The receiving unit 51 is configured to receive a frequency domainresource indication value RIV of a data channel from a network device,where the RIV is used to indicate a frequency domain resource positionof the data channel, the RIV is related to a quantity

N_(BWP)^(RBG)

of resource block groups RBGs in a bandwidth part BWP, and

N_(BWP)^(RBG)

is related to a quantity

N_(BWP)^(size)

of RBs included in the BWP and an RBG size P.

The processing unit 52 is configured to determine a frequency domainresource position of the data channel based on the RIV.

The receiving unit 51 is further configured to receive the data channelfrom the network device at the frequency domain resource position.

The sending unit 53 is configured to send a data channel to the networkdevice at the frequency domain resource position.

In an implementation, the receiving unit 51 is further configured toreceive first indication information from the network device, where thefirst indication information is used to indicate one of at least two RBGsizes corresponding to a range of the quantity of RBs included in theBWP.

In another implementation, the receiving unit 51 is further configuredto receive P from the network device.

In still another implementation, the processing unit 52 is configured todetermine the RIV by using the following formula:

$\begin{array}{l}{\text{if}\mspace{6mu}\left( {\text{L}_{RBG}\mspace{6mu} - \mspace{6mu} 1} \right)\mspace{6mu} \leq \mspace{6mu}\left( \left\lfloor {N_{BWP}^{RBG}\text{/}2} \right\rfloor \right),\mspace{6mu}\text{then}} \\{\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu} RIV = N_{BWP}^{RBG}\mspace{6mu}\left( {\text{L}_{RBG}\mspace{6mu} - \mspace{6mu} 1} \right)\mspace{6mu} + \mspace{6mu} RBG_{Start}} \\\text{else} \\{\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu}\mspace{6mu} RIV = N_{BWP}^{RBG}\mspace{6mu}\left( {N_{BWP}^{RBG}\mspace{6mu} - \mspace{6mu}\text{L}_{RBG}\mspace{6mu} + \mspace{6mu} 1} \right)\mspace{6mu} + \mspace{6mu}\left( {N_{BWP}^{RBG}\mspace{6mu} - \mspace{6mu} 1\mspace{6mu} - \mspace{6mu} RBG_{Start}} \right)}\end{array}$

where L_(RBG) represents a quantity of RBGs occupied by a frequencydomain of a data channel, and L_(RBG) ≥ 1;

N_(BWP)^(RBG) = ⌈N_(BWP)^(size)/P⌉,

and represents a quantity of RBGs in a BWP;

N_(BWP)^(size)

is a quantity of RBs included in the BWP, and P is an RBG size, namely,a quantity of RBs included in one RBG; RBG_(Start) is a starting RBGnumber of the frequency domain of the data channel; and L_(RBG) ≤

N_(BWP)^(RBG)

RBG_(Start).

For more detailed descriptions of the receiving unit 51, the processingunit 52, and the sending unit 53, directly refer to related descriptionsof the terminal device in the method embodiment shown in FIG. 5 , anddetails are not described herein again.

Based on a same concept as that of the communication method in theforegoing embodiment, as shown in FIG. 11 , an embodiment of thisapplication further provides a communications apparatus 6000. Thecommunications apparatus may be applied to the communication methodshown in FIG. 5 . The communications apparatus 6000 may be the networkdevice 100 shown in FIG. 2 , or may be a component (for example, a chip)applied to the network device 100. The communications apparatus 6000includes a processing unit 61, a sending unit 62, and a receiving unit63.

The processing unit 61 is configured to determine a frequency domainresource indication value RIV of a data channel, where the RIV is usedto indicate a frequency domain resource position of the data channel,the RIV is related to a quantity

N_(BWP)^(RBG)

of resource block groups RBGs in a bandwidth part BWP, and

N_(BWP)^(RBG)

is related to a quantity

N_(BWP)^(size)

of RBs included in the BWP and an RBG size P.

The sending unit 62 is configured to send the RIV to a terminal device.

The sending unit 62 is further configured to send the data channel tothe terminal device at the frequency domain resource position indicatedby the RIV.

The receiving unit 63 is configured to receive a data channel from theterminal device at the frequency domain resource position.

In an implementation, the sending unit 62 is further configured to sendfirst indication information to the terminal device, where the firstindication information is used to indicate one of at least two RBG sizescorresponding to a range of the quantity of RBs included in the BWP.

In another implementation, the sending unit 62 is further configured tosend P to the terminal device.

In still another implementation, the processing unit 61 is configured todetermine the RIV by using the following formula:

$\begin{array}{l}{\text{if}\left( {\text{L}_{RBG} - 1} \right) \leq \left( \left\lfloor {N_{BWP}^{RBG}/2} \right\rfloor \right)\text{, then}} \\{\quad\quad\quad\quad\quad\quad RIV = N_{BWP}^{RBG}\left( {\text{L}_{RBG} - 1} \right) + RBG_{Start}} \\\text{else} \\{\quad\quad\quad RIV = N_{BWP}^{RBG}\left( {N_{BWP}^{RBG} - \text{L}_{RBG} + 1} \right) + \left( {N_{BWP}^{RBG} - 1 - RBG_{Start}} \right)}\end{array}$

where L_(RBG) represents a quantity of RBGs occupied by a frequencydomain of a data channel, and L_(RBG) ≥ 1;

N_(BWP)^(RBG) = ⌈N_(BWP)^(size)/P⌉,

and represents a quantity of RBGs in a BWP;

N_(BWP)^(size)

is a quantity of RBs included in the BWP, and P is an RBG size, namely,a quantity of RBs included in one RBG; RBG_(Start) is a starting RBGnumber of the frequency domain of the data channel; and L_(RBG) ≤

N_(BWP)^(RBG)

RBG_(Start).

For more detailed descriptions of the processing unit 61, the sendingunit 62, and the receiving unit 63, directly refer to relateddescriptions of the network device in the method embodiment shown inFIG. 5 , and details are not described herein again.

An embodiment of this application further provides a communicationsapparatus. The communications apparatus is configured to perform theforegoing communication methods. Some or all of the foregoingcommunication methods may be implemented by using hardware, or may beimplemented by using software.

Optionally, during specific implementation, the communications apparatusmay be a chip or an integrated circuit.

Optionally, when some or all of the communication methods in theforegoing embodiments are implemented by using software, thecommunications apparatus includes: a memory, configured to store aprogram; and a processor, configured to execute the program stored inthe memory, so that when the program is executed, the communicationsapparatus is enabled to implement the communication methods provided inthe foregoing embodiments.

Optionally, the memory may be a physically independent unit, or may beintegrated with the processor.

Optionally, when some or all of the communication methods in theforegoing embodiments are implemented by using software, thecommunications apparatus may alternatively include only a processor. Amemory configured to store a program is located outside thecommunications apparatus. The processor is connected to the memory byusing a circuit/wire, and is configured to read and execute the programstored in the memory.

The processor may be a central processing unit (CPU), a networkprocessor (NP), or a combination of a CPU and an NP.

The processor may further include a hardware chip. The hardware chip maybe an application-specific integrated circuit (ASIC), a programmablelogic device (PLD), or a combination thereof. The PLD may be a complexprogrammable logic device (CPLD), a field -programmable gate array(FPGA), generic array logic (GAL), or any combination thereof.

The memory may include a volatile memory, for example, a random-accessmemory (RAM). The memory may alternatively include a non-volatilememory, for example, a flash memory, a hard disk drive (HDD), or asolid-state drive (SSD). The memory may alternatively include acombination of the foregoing types of memories.

FIG. 12 is a simplified schematic structural diagram of a terminaldevice. For ease of understanding and illustration, an example in whichthe terminal device is a mobile phone is used in FIG. 12 . As shown inFIG. 12 , the terminal device includes a processor, a memory, a radiofrequency circuit, an antenna, and an input/output apparatus. Theprocessor is mainly configured to: process a communications protocol andcommunications data, control the terminal device, execute a softwareprogram, process data of the software program, and so on. The memory ismainly configured to store a software program and data. The radiofrequency circuit is mainly configured to: perform conversion between abaseband signal and a radio frequency signal, and process the radiofrequency signal. The antenna is mainly configured to receive and send aradio frequency signal in a form of an electromagnetic wave. Theinput/output apparatus such as a touchscreen, a display, or a keyboardis mainly configured to receive data entered by a user and output datato the user. It should be noted that some types of terminal devices mayhave no input/output apparatus.

When data needs to be sent, after performing baseband processing on theto-be-sent data, the processor outputs a baseband signal to the radiofrequency circuit; and the radio frequency circuit performs radiofrequency processing on the baseband signal and then sends a radiofrequency signal to the outside in a form of an electromagnetic wave byusing the antenna. When data is sent to the terminal device, the radiofrequency circuit receives a radio frequency signal through the antenna,converts the radio frequency signal into a baseband signal, and outputsthe baseband signal to the processor; and the processor converts thebaseband signal into data, and processes the data. For ease ofdescription, FIG. 12 shows only one memory and one processor. In anactual terminal device product, there may be one or more processors andone or more memories. The memory may also be referred to as a storagemedium, a storage device, or the like. The memory may be disposedindependent of the processor, or may be integrated with the processor.This is not limited in this embodiment of this application.

In this embodiment of this application, the antenna and the radiofrequency circuit that have receiving and sending functions may beconsidered as a receiving unit and a sending unit (which may also becollectively referred to as a transceiver unit) of the terminal device,and the processor having a processing function may be considered as aprocessing unit of the terminal device. As shown in FIG. 12 , theterminal device includes a receiving unit 71, a processing unit 72, anda sending unit 73. The receiving unit 71 may also be referred to as areceiver, a receiver machine, a receiver circuit, or the like. Thesending unit 73 may also be referred to as a transmitter, a transmittingdevice, a transmitter machine, a transmitting circuit, or the like. Theprocessing unit may also be referred to as a processor, a processingboard, a processing module, a processing apparatus, or the like.

For example, in an embodiment, the receiving unit 71 is configured toperform functions of the terminal device in steps S101, S102, and S103 ain the embodiment shown in FIG. 3 ; and the sending unit 73 isconfigured to perform a function of the terminal device in step S103 bin the embodiment shown in FIG. 3 .

For another example, in another embodiment, the receiving unit 71 isconfigured to perform functions of the terminal device in steps S201 andS203 a in the embodiment shown in FIG. 4 ; the processing unit 72 isconfigured to perform step S202 in the embodiment shown in FIG. 4 ; andthe sending unit 73 is configured to perform a function of the terminaldevice in step S203 b in the embodiment shown in FIG. 4 .

For another example, in still another embodiment, the receiving unit 71is configured to perform functions of the terminal device in steps S302and S303 a in the embodiment shown in FIG. 5 ; and the sending unit 73is configured to perform a function of the terminal device in step S303b in the embodiment shown in FIG. 5 .

FIG. 13 is a simplified schematic structural diagram of a networkdevice. The network device includes a part 82 and a part for radiofrequency signal receiving/sending and conversion. The part for radiofrequency signal receiving and sending and conversion further includes areceiving unit 81 and a sending unit 83 (which may also be collectivelyreferred to as a transceiver unit). The part for radio frequency signalreceiving/sending and conversion is mainly configured to: send/receive aradio frequency signal and perform conversion between a radio frequencysignal and a baseband signal. The part 82 is mainly configured toperform baseband processing, control the network device, and so on. Thereceiving unit 81 may also be referred to as a receiver, a receivermachine, a receiving circuit, or the like. The sending unit 83 may alsobe referred to as a transmitter, a transmitting device, a transmittermachine, a transmitting circuit, or the like. The part 82 is usually acontrol center of the network device, and may usually be referred to asa processing unit, configured to control the network device to performsteps performed by the network device in FIG. 3 , FIG. 4 , or FIG. 5 .For details, refer to the foregoing descriptions of the related parts.

The part 82 may include one or more boards. Each board may include oneor more processors and one or more memories. The processor is configuredto read and execute a program in the memory to implement a basebandprocessing function and control the network device. If there are aplurality of boards, the boards may be interconnected to enhance aprocessing capability. In an optional implementation, alternatively, theplurality of boards may share one or more processors, or the pluralityof boards share one or more memories.

For example, in an embodiment, the sending unit 83 is configured toperform functions of the network device in steps S101, S102, and S103 ain the embodiment shown in FIG. 3 ; and the receiving unit 81 isconfigured to perform a function of the network device in step S103 b inthe embodiment shown in FIG. 3 .

For another example, in another embodiment, the sending unit 83 isconfigured to perform functions of the network device in steps S201 andS203 a in the embodiment shown in FIG. 4 ; and the receiving unit 81 isconfigured to perform a function of the network device in step S203 b inthe embodiment shown in FIG. 4 .

For another example, in still another embodiment, the processing unit 82is configured to perform step S301 in the embodiment shown in FIG. 5 ;the sending unit 83 is configured to perform functions of the networkdevice in steps S302 and S303 a in the embodiment shown in FIG. 5 ; andthe receiving unit 81 is configured to perform a function of the networkdevice in step S303 b in the embodiment shown in FIG. 5 .

A person skilled in the art may clearly understand that for the purposeof convenient and brief description, for detailed working processes ofthe foregoing system, apparatus, and unit, refer to correspondingprocesses in the foregoing method embodiments, and details are notdescribed herein again.

In the several embodiments provided in this application, it should beunderstood that the disclosed system, apparatus, and method may beimplemented in other manners. For example, the unit division is merelylogical function division and there may be another division duringactual implementation. For example, a plurality of units or componentsmay be combined or integrated into another system, or some features maybe ignored or not performed. In addition, the displayed or discussedmutual couplings, direct couplings, or communication connections may beimplemented by using some interfaces. The indirect couplings orcommunication connections between the apparatuses or units may beimplemented in electronic, mechanical, or other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on a plurality ofnetwork units. Some or all of the units may be selected based on actualrequirements to achieve the objectives of the solutions of theembodiments.

All or some of the foregoing embodiments may be implemented by usingsoftware, hardware, firmware, or any combination thereof. When softwareis used to implement the embodiments, the embodiments may be implementedcompletely or partially in a form of a computer program product. Thecomputer program product includes one or more computer instructions.When the computer program instructions are loaded and executed on thecomputer, the procedure or functions according to the embodiments ofthis application are all or partially generated. The computer may be ageneral-purpose computer, a dedicated computer, a computer network, orother programmable apparatuses. The computer instruction may be storedin a computer-readable storage medium, or may be transmitted by using acomputer-readable storage medium. The computer instructions may betransmitted from one website, computer, server, or data center toanother website, computer, server, or data center in a wired (forexample, a coaxial cable, an optical fiber, or a digital subscriber line(DSL)) or wireless (for example, infrared, radio, or microwave) manner.The computer storage medium may be any usable medium accessible by acomputer, or a data storage device, such as a server or a data center,integrating one or more usable media. The usable medium may be aread-only memory (ROM), a random access memory (RAM), or a magneticmedium such as a floppy disk, a hard disk, a magnetic tape, a magneticdisk, or an optical medium such as a digital versatile disc (DVD), or asemiconductor medium such as a solid-state disk (SSD).

1. An apparatus comprising: at least one processor; and a non-transitorycomputer readable medium storing a program executable by the at leastone processor, the program comprising instructions for: receiving afrequency domain resource indication value (RIV) of a data channel froma network device, wherein the RIV indicates a frequency domain resourceposition of the data channel, the RIV is related to a quantityN_(BWP)^(RBG) of resource block groups (RBGs) in a bandwidth part (BWP),and N_(BWP)^(RBG) is related to a quantity N_(BWP)^(size) of resourceblocks (RBs) comprised in the BWP and to an RBG size P; determining thefrequency domain resource position of the data channel based on the RIV;and sending the data channel to the network device on the frequencydomain resource position or receiving the data channel from the networkdevice on the frequency domain resource position.
 2. The apparatusaccording to claim 1, wherein the program further comprises instructionsfor: receiving indication information indicating P.
 3. The apparatusaccording to claim 1, wherein when (L_(RBG) - 1) ≤ [ N_(BWP)^(RBG) /2],RIV = N_(BWP)^(RBG) (L_(RBG) - 1) + RBG_(Start), and when(L_(RBG) - 1) > [ N_(BWP)^(RBG) /2],RIV = N_(BWP)^(RBG)(N_(BWP)^(RBG)) -L_(RBG) + 1) + ( N_(BWP)^(RBG) - 1 - RBG_(Start)), wherein L_(RBG)represents a quantity of RBGs occupied by a frequency domain of the datachannel, and L_(RBG) ≥ 1; N_(BWP)^(RBG) represents the quantity of RBGsin the BWP; RBG_(Start) is a starting RBG number of the frequency domainof the data channel; and L_(RBG) ≤ N_(BWP)^(RBG) - RBG_(Start).
 4. Acommunications method comprising: determining a frequency domainresource indication value (RIV) of a data channel, wherein the RIVindicates a frequency domain resource position of the data channel, theRIV is related to a quantity N_(BWP)^(RBG) of resource block groups(RBGs) in a bandwidth part (BWP), and N_(BWP)^(RBG) is related to aquantity N_(BWP)^(size) of resource blocks (RBs) comprised in the BWPand to an RBG size P; sending the RIV to a terminal device; and sendingthe data channel to the terminal device on the frequency domain resourceposition indicated by the RIV or receiving the data channel from theterminal device on the frequency domain resource position indicated bythe RIV.
 5. The method according to claim 4, further comprising: sendingindication information indicating P to the terminal device.
 6. Themethod according to claim 4, wherein when (L_(RBG) - 1) ≤ [N_(BWP)^(RBG) /2], RIV = N_(BWP)^(RBG) (L_(RBG) - 1) + RBG_(Start), andwhen (L_(RBG) - 1) > [ N_(BWP)^(RBG) /2], RIV =N_(BWP)^(RBG)(N_(BWP)^(RBG)) - L_(RBG) + 1) + ( N_(BWP)^(RBG) - 1 -RBG_(Start)), wherein L_(RBG) represents a quantity of RBGs occupied bya frequency domain of the data channel, and L_(RBG) ≥ 1; N_(BWP)^(RBG)represents the quantity of RBGs in the BWP; RBG_(Start) is a startingRBG number of the frequency domain of the data channel; and L_(RBG) ≤N_(BWP)^(RBG) - RBG_(Start).
 7. An apparatus comprising: at least oneprocessor; and a non-transitory computer readable medium storing aprogram executable by the at least one processor, the program comprisinginstructions for: determining a frequency domain resource indicationvalue (RIV) of a data channel, wherein the RIV indicates a frequencydomain resource position of the data channel, the RIV is related to aquantity N_(BWP)^(RBG) of resource block groups (RBGs) in a bandwidthpart (BWP), and N_(BWP)^(RBG) is related to a quantity N_(BWP)^(size) ofresource blocks (RBs) comprised in the BWP and to an RBG size P; sendingthe RIV to a terminal device; and sending the data channel to theterminal device on the frequency domain resource position indicated bythe RIV or receiving the data channel from the terminal device on thefrequency domain resource position indicated by the RIV.
 8. Theapparatus according to claim 7, wherein the program comprises furtherinstructions for: sending indication information indicating P to theterminal device.
 9. The apparatus according to claim 7, wherein when(L_(RBG) - 1) ≤ [ N_(BWP)^(RBG) /2]), RIV = N_(BWP)^(RBG)(L_(RBG) - 1) + RBG_(Start), and when (L_(RBG) - 1) > [ N_(BWP)^(RBG)/2], RIV = N_(BWP)^(RBG)(N_(BWP)^(RBG)) - L_(RBG) + 1) + (N_(BWP)^(RBG) - 1 - RBG_(Start)), wherein L_(RBG) represents a quantityof RBGs occupied by a frequency domain of the data channel, and L_(RBG)≥ 1; N_(BWP)^(RBG) represents the quantity of RBGs in the BWP;RBG_(Start) is a starting RBG number of the frequency domain of the datachannel; and L_(RBG) ≤ N_(BWP)^(RBG) - RBG_(Start).